This Research Training Grant renewal application is an extensively revised resubmission of our initial proposal to support cross-disciplinary and comprehensive dental science research training at the School of Dentistry at the University of Washington. The application constitutes the competing renewal of the former Oral Biology-Salivary Research Training and the Bacterially Induced Chronic Inflammation Research Training grants. The revised application consists of a single research training facility and program, focused on using molecular and cell biology and bioengineering approaches to study the basic biology of the oral tissues and their reactions to microbial pathogens and inert materials. The Program is administered by a Program Coordinator, and directed by a Program Oversight Committee. The collaborating Training Faculty include individuals from the Schools of Dentistry, Medicine, Public Health and the Department of Bioengineering; and are organized into 12 groups based on research interests. The proposed training program consists of two phases: 1) All trainees will receive coursework in the major competency areas cited in the PA including: genomics, molecular biology and molecular epidemiology, gene-mediated diagnosis and therapeutics, cell biology, bioinformatics, biomaterials, biomimetics, nanotechnology, tissue engineering and bioimaging technology. Coursework will also include experimental design and data analysis, and dental sciences. PhD students will receive the most training; MS and short-term trainees will receive less. 2) All trainees will learn to perform biological experiments using molecular and cell biology and/or bioengineering approaches by designing and performing experiments under the direction of a Research Mentor chosen from the proposed training faculty. A total of 12.75 training positions are requested, of which 6 are postdoctoral and 5 are predoctoral long term positions, 1.5 are short term positions for dental students, and 0.25 are short term positions for new and midcareer dental school faculty. Although long term trainees may elect to matriculate in a PhD or MS (dentists only) programs in 6 departments, Oral Biology and Bioengineering are expected to have highest enrollments. Courses to be taken in conjunction with this training are described in some detail.